Therapeutic Effects of Amaranth: Analysis of the Antidiabetic Potential of the Plant

Amaranth is a pseudocereal rich in macronutrients and micronutrients, with about 60 species cultivated worldwide. It is a high nutritional value food because of its many essential amino acids. Recent investigations demonstrate that the phytochemicals and extracts of amaranth have beneficial effects on health, including antidiabetic potential, a decrease in plasmatic cholesterol and blood pressure, and protection from oxidative stress and inflammation. Nowadays, type 2 diabetes has increased worldwide, becoming a problem of public health that makes it necessary to look for alternative strategies for its prevention and treatment. This review aims to summarize the antidiabetic potential of diverse species of the Amaranth genus. A bibliographical review was updated on the plant's therapeutic potential, including stem, leaves, and seeds, to know the benefits and potential as an adjuvant in treating and managing diabetes and associated pathologies (hypertension, dyslipidemia, and heart disease). This analysis contributes to the generation of knowledge about the therapeutic effects of amaranth, promoting the creation of new products, and the opportunity to conduct clinical trials to assess their safety and efficacy.

Colorant Pigments, Nutrients, Bioactive Components, and Antiradical Potential of Danta Leaves (Amaranthus lividus)

In the Indian subcontinent, danta (stems) of underutilized amaranth are used as vegetables in different culinary dishes. At the edible stage of the danta, leaves are discarded as waste in the dustbin because they are overaged. For the first time, we assessed the colorant pigments, bioactive components, nutrients, and antiradical potential (AP) of the leaves of danta to valorize the by-product (leaf) for antioxidant, nutritional, and pharmacological uses. Leaves of danta were analyzed for proximate and element compositions, colorant pigments, bioactive constituents, AP (DPPH), and AP (ABTS⁺). Danta leaves had satisfactory moisture, protein, carbohydrates, and dietary fiber. The chosen danta leaves contained satisfactory magnesium, iron, calcium, potassium, manganese, copper, and zinc; adequate bioactive pigments, such as betacyanins, carotenoids, betalains, β-carotene, chlorophylls, and betaxanthins; and copious bioactive ascorbic acid, polyphenols, flavonoids, and AP. The correlation coefficient indicated that bioactive phytochemicals and colorant pigments of the selected danta leaves had good AP as assessed via ABTS⁺ and DPPH assays. The selected danta leaves had good ROS-scavenging potential that could indicate massive possibilities for promoting the health of the nutraceutical- and antioxidant-deficit public. The findings showed that danta leaves are a beautiful by-product for contributing as an alternate origin of antioxidants, nutrients, and bioactive compounds with pharmacological use.

Phytonutrients, Colorant Pigments, Phytochemicals, and Antioxidant Potential of Orphan Leafy Amaranthus Species

The underutilized Amaranthus leafy vegetables are a unique basis of pigments such as β-cyanins, β-xanthins, and betalains with radical scavenging capacity (RSC). They have abundant phytonutrients and antioxidant components, such as pigments, vitamins, phenolics, and flavonoids. Eight selected genotypes (four genotypes from each species) of underutilized Amaranthus leafy vegetables were evaluated for phytonutrients, pigments, vitamins, phenolics, flavonoids, and antioxidants in a randomized complete block design under ambient field conditions with three replicates. The studied traits showed a wide range of variations across eight genotypes of two species of Amaranthus leafy vegetables. The highest fat, β-xanthins, K, dietary fiber, Mg, β-cyanins, Mn, chlorophyll ab, Zn, TP, TF, betalains, chlorophyll a content, and (RSC) (DPPH) and RSC (ABTS+) were obtained from A. tricolor accessions. Conversely, the highest protein, Cu, carbohydrates, Ca, and chlorophyll b content were obtained from A. lividus accessions. The highest dry matter, carotenoids, Fe, energy, and ash were obtained from A. tricolor and A. lividus. The accession AT2 confirmed the highest vit. C and RSC (DPPH) and RSC (ABTS+); AT5 had the highest TP content; and AT12 had the highest TF content. A. tricolor accessions had high phytochemicals across the two species, such as phytopigments, vitamins, phenolics, antioxidants, and flavonoids, with considerable nutrients and protein. Hence, A. tricolor accessions can be used as high-yielding cultivars comprising ample antioxidants. The correlation study revealed that vitamin C, pigments, flavonoids, β-carotene, and phenolics demonstrated a strong RSC, and showed a substantial contribution to the antioxidant potential (AP) of A. tricolor. The investigation exposed that the accessions displayed a plentiful origin of nutritional values, phytochemicals, and AP with good quenching ability of reactive oxygen species (ROS) that provide enormous prospects for nourishing the mineral-, antioxidant-, and vitamin-threatened community.

The Effect of Juicing Methods on the Phytochemical and Antioxidant Characteristics of the Purple Prickly Pear (Opuntia ficus indica)—Preliminary Findings on Juice and Pomace

Prickly Pear (PP) is often overlooked due to its’ short shelf-life. Juicing may improve marketability but often affects quality, thereby warranting investigation. Purple PP (whole (WF) and flesh (FF)) was juiced using blenders; stick (SB) and jug (JB); and juicers; commercial (CJ) and cold-pressed (CP). Juices and methanolic (70%) pomace extracts were analysed for; bioactives; Total Phenolic (TPC; µgGAE/mL), Flavonoid (TFC; µgCE/mL) and Betalain Content (TBC; mg/100 g; Betacyanin; BE; Betaxanthin; IE); and antioxidant characteristics; DPPH, FRAP (µMTE) and vitamin C (mgAAE/mL). Juicing techniques had effects on phytochemicals in; juice: TPC (WF/FF; p = 0.022–0.025), TFC (FF; p = 0.034), Betacyanin (WF/FF; p = 0.029–0.026), FRAP (WF/FF; p = 0.016–0.024) and Vitamin C (WF/FF; p = 0.015–0.016); and pomace: TPC (WF/FF; p = 0.015), TBC (FF; p = 0.034), Betacyanin (FF; p = 0.047), Betaxanthin (FF; p = 0.017), DPPH (WF/FF; p = 0.016–0.024), FRAP (WF/FF; p = 0.015–0.023) and Vitamin C (WF/FF; p = 0.016–0.022). Processing-style (blend/juice) affected; TPC, DPPH and FRAP in juice and pomace. Overall, fruit-preparation (WF/FF) had minimal effects. Additionally, correlations existed between; juice TFC and TBC (p = 0.001; τ = −0.044); TBC and vitamin C (p = 0.001; τ = −0.637); pomace TPC and DPPH (p = 0.003; τ = 0.440), TPC and vitamin C (p = 0.011; τ = 0.440); and TFC and FRAP (p = 0.001; τ = 0.519). The best methods overall for juice were SB (FRAP), JB (TPC, TBC), CJ (TFC) and CP (DPPH, VitC); and for pomace extracts; SB(FRAP), JB (TPC, VitC), CJ(TFC), and CP (TBC, DPPH).